Aspergillus Niger Strain Research Articles

Safety evaluation of the food enzyme containing endo-polygalacturonase, pectinesterase, pectin lyase and non-reducing end α-l-arabinofuranosidase activities from the Aspergillus niger strain PEC.

The food enzyme has four declared activities (endo‐polygalacturonase ((1→4)‐α‐d‐galacturonan glycanohydrolase (endo‐cleaving); 3.2.1.15), pectinesterase (pectin pectylhydrolase; 3.1.1.11), pectin lyase ((1→4)‐6‐O‐methyl‐α‐d‐galacturonan lyase; 4.2.2.10) and non‐reducing end α‐l‐arabinofuranosidase (α‐l‐arabinofuranoside non‐reducing end α‐l‐arabinofuranosidase; 3.2.1.55) and is produced with the non‐genetically modified Aspergillus niger strain PEC by DSM Food Specialties B.V. The food enzyme is free from viable cells of the production organism. The food enzyme is intended to be used in the manufacture of alcoholic beverages from fruits other than grapes, fruit and vegetable processing for juice production, and wine and wine vinegar production. Dietary exposure was estimated to be up to 0.25 mg TOS/kg bodyweight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 204 mg TOS/kg bw per day, the highest dose tested which, when compared with the estimated dietary exposure, results in a margin of exposure of at least 800. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and several matches were found. The Panel considered that, under the intended conditions of use, the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, particularly for individuals sensitised to several pollen allergens or papaya allergens. Based on the data provided, the Panel concluded that this food enzyme did not give rise to safety concerns, under the intended conditions of use.

Molecular docking and nucleotide sequencing of successive expressed recombinant fungal peroxidase gene in E.coli

BackgroundFungal peroxidases are oxidoreductases that utilize hydrogen peroxide to catalyze lignin biodegradation. ResultsPER-K (peroxidase synthesis codon gene) was transformed from Aspergillus niger strain AN512 deposited in the National Center for Biotechnology Information with the accession number OK323140 to Escherichia coli strain (BL21-T7 with YEp356R recombinant plasmid) via calcium chloride heat-shock method. The impact of four parameters (CaCl2 concentrations, centrifugation time, shaking speed, growth intensity) on the efficacy of the transformation process was evaluated. Furthermore, peroxidase production after optimization was assessed both qualitatively and quantitatively, as well as SDS-PAGE analysis. The optimum conditions for a successful transformation process were as follows: CaCl2 concentrations (50 mM), centrifugation time (20 min), shaking speed (200 rpm), and growth optical density (0.45). PCR and gel electrophoresis detect DNA bands with lengths 175, 179, and 211 bps corresponding to UA3, AmpR, and PER-K genes respectively besides partially sequencing the PER-K gene. Pyrogallol/hydrogen peroxide assay confirmed peroxidase production, and the activity of the enzyme was determined to be 3924 U/L. SDS-PAGE analysis also confirms peroxidase production illustrated by the appearance of a single peroxidase protein band after staining with Coomassie blue R-250. ConclusionA successful peroxidase-gene (PER-K) transformation from fungi to bacteria was performed correctly. The enzyme activity was screened, and partial sequencing of PER-K gene was analyzed successively. The protein 3D structure was generated via in silico homology modeling, and determination of binding sites and biological annotations of the constructed protein were carried out via COACH and COFACTOR based on the I-TASSER structure prediction.

MICROWAVE ASSISTED SOLVENT FREE SYNTHESIS AND EVALUATION OF ANTIMICROBIAL AND ANTIOXIDANT ACTIVITIES OF SOME NOVEL 3, 4-BIS (SUBSTITUTED PHENYL)-7-(6-METHYL PYRIDIN-2-YL)-3, 3A, 3B, 4-TETRAHYDRO7H-PYRROLO [2, 3-C : 5,4-C']DIISOXAZOLE

Novel heterocyclic compounds were synthesized, characterized and screened for antimicrobial activity and antioxidant activity. This series of novel bis-isoxazole derivatives were synthesized via reaction of bis chalcone of succinimide treated with hydroxyl amine hydrochloride in presence of neutral alumina by microwave assisted solvent free method in good yield. It was observed that microwave assisted method produced a greater yield of products in shorter reaction times. The structures of synthesized compounds were characterized by their spectral analyses (elemental analysis, FTIR, 1H NMR) and the purity of synthesized compounds were confirmed by TLC. All the synthesized compounds were evaluated for antimicrobial activity against gram positive bacteria Staphylococcus aureus (NCIM 2079) and gram negative bacteria Escherichia coli (NCIM 2109) using DMSO solvent and antifungal activity against fungal strain Aspergillus Niger (NCIM 545). Most of the synthesized compounds exhibited a moderate grade of anti-microbial activity. The study concluded that the compound 4c exhibited potent anti-bacterial activity when compared to Chloramphenicol as standard drug while compound 4b, 4c, 5b, 5c, 5e exhibited significant anti-fungal activity when compared to Amphotericin B as standard drug. All the synthesized compounds were screened for their antioxidant activities. Among them, compounds 4a, 4e, 5a, 5b, 5c and 5e showed moderate to good antioxidant activity when compared to ascorbic acid as standard drug.

Phytochemical Screening and In Vitro Antifungal Activity of Selected Medicinal Plants against Candida albicans and Aspergillus niger in West Shewa Zone, Ethiopia.

Antimicrobial resistance to commercially available medications has become a global issue, yet there is still the possibility of developing new drugs from medicinal plants. As a result, the aims of the present study were to screen secondary metabolites and to evaluate in vitro antifungal activities of Brucea antidysenterica, Aloe vera, and Justicia schimperiana. After the plants were identified, their leaves were collected, washed, dried under the shade, pulverized, and extracted with methanol (99.8%) using the maceration technique. The presence of secondary metabolites in plant extracts was screened using various laboratory protocols. The antifungal activities of the plant extract against reference fungal strains of Candida albicans and Aspergillus niger at concentrations of 200, 100, and 50 mg/mL were assessed using the agar-well diffusion method. Ketoconazole (15 μg) was used as a positive control, while 5% dimethyl sulfoxide and/or 5% Tween 80 were used as negative controls. All tests were conducted in triplicate. Alkaloids, flavonoids, and phenols were secondary metabolites found in all plant extracts. The extract of leaves of B. antidysenterica and J. schimperiana formed a mean zone of inhibition of 15.5 ± 0.5 mm and 15.3 ± 0.58 mm, respectively, against Candida albicans at a concentration of 200 mg/mL, whereas extracts of A. vera leaves formed a 12.3 ± 0.58 mm inhibition zone only against Aspergillus niger at 200 mg/mL. In conclusion, the current study found that B. antidysenterica, A. vera, and J. schimperiana had antifungal activity. In addition, all these plants had a variety of secondary metabolites that possibly have antifungal activities. Studies on in vivo investigations and isolation of specific antifungal compounds from these medicinal plants are suggested.

4a-methyl-dodecahydro-1H-pyrrolo[3,4-b]quinoline-6-one produced by Endophytic Fungi Aspergillus niger E12 obtained from Dodonaea viscosa Plant Leaves as a Novel Antibacterial Compound.

Endophytic fungi were isolated from forty plant leaf samples from Gudiyam forest. The potent antibacterial strain Aspergillus niger E12 isolated from the plant Dodonaea viscosa showed maximal antibacterial activity against all the test organisms, viz., Staphylococcus aureus, Bacillus coagulans, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The production of the antibacterial compound was optimized using the yeast extract sucrose medium (2% YES) using response surface methodology (RSM). For the production, the optimal parameters were carbon/nitrogen (C:N) ratio, 9:1; temperature, 25°C; pH, 5.7; incubation time, 240h; and rpm, 30. A zone of inhibition of 19.33mm was observed as maximal bioactivity against Pseudomonas aeruginosa. The antibacterial compound was purified by extraction with ethyl acetate, activity-guided fractionation, and preparative high-performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) studies showed that the Aspergillus niger E12 bioactive substance is 4a-methyl-dodecahydro-1H-pyrrolo [3,4-b] quinoline-6-one.

Design, Synthesis, Biological evaluation of Isonicotinoyl-pyrazolyl-coumarin derivatives and computational study

• A series of new Scaffold isonicotinoyl-pyrazolyl-coumarin dyads was synthesized. • The structures of the new hybrid compounds were performed by spectroscopic means. • All the compounds were screened in vitro for their potential Antifungal and Antioxidant activities. • Theoretical calculations were done for the molecules geometries. • Synthesized compounds were docked with fungal protein (Phytase A) from Aspergillus niger using AutoDock 4 software A new series of 3-(5-Hydroxy-1-isonicotinoyl-3-methyl-4,5-dihydro-1 H -pyrazol-5-yl)-2 H -chromen-2-one derivatives 3a-g was efficiently synthesized under environmentally friendly reaction conditions by reaction of 3-acetoacetylcoumarin derivatives 1a-g with isoniazid 2 . The reaction is conveniently performed at room temperature using Knorr pyrazole syntheses. The key features of this approach are its operational simplicity, the facile access to the desired products, and the good to excellent yields. The structures of the newly synthesized compounds were established by 1 H, 13 C, 2D NMR spectroscopy and mass spectrometry. 1 H- 15 N HMBC experiments were also conducted to assess the regiochemistry of final compounds. All the synthesized compounds were evaluated for their in vitro antifungal activity against both Candida albicans and Aspergillus niger strains and compared to the standard drug Ketoconazole. Among all the compounds, 3d and 3e were the most effective, showing high potential antigungal inhibitory activities with respective MIC values of 15.62 µg ml −1 for 3e against Aspergillus niger. All the newly synthesized derivatives 3a-g are evaluated for their antioxidant activity and showed good activity. SAR studies demonstrated that the presence of nitro and hydroxyl groups in the aromatic ring of the coumarin and pyrazoline rings conferred enhanced antioxidant and antifungal activity. In addition, molecular docking studies were performed for compound 3e to evaluate its potential as an inhibitor of the fungal protein (Phytase A) from Aspergillus niger and the results suggested that our isonicotinoyl-pyrazolyl-coumarin may act as promising antifungal agent.

Safety evaluation of the food enzyme glucan 1,4-α-glucosidase from Aspergillus niger.

The food enzyme glucan 1,4‐α‐glucosidase (4‐α‐d‐glucan glucohydrolase, EC 3.2.1.3) is produced with a non‐genetically modified strain of Aspergillus niger by Beijing Shifa Technology & Trade Co., Ltd. The food enzyme is intended to be used in baking processes, cereal‐based processes, brewing processes, fruit and vegetable processing for juice production, distilled alcohol production, starch processing for the production of glucose syrups and other starch hydrolysates, and yeast processing. In the absence of data sufficient to characterise the source of food enzyme, its method of production, its chemical characterization and its potential allergenicity, coupled with the absence of study reports for toxicological data and insufficient information about food manufacturing processes, the Panel was unable to assess the safety of the food enzyme glucan 1,4‐α‐glucosidase from an unknown strain of Aspergillus niger.

Safety evaluation of the food enzyme glucan 1,4-α-glucosidase from the genetically modified Aspergillus niger strain NZYM-BE.

The food enzyme glucan 1,4‐α‐glucosidase (4‐α‐d‐glucan glucohydrolase EC 3.2.1.3) is produced with the genetically modified Aspergillus niger strain NZYM‐BE by Novozymes A/S. The genetic modifications do not give rise to safety concerns. The food enzyme was free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in six food manufacturing processes, namely starch processing for the production of glucose syrups and other starch hydrolysates, distilled alcohol production, brewing processes, baking processes, cereal‐based processes, and fruit and vegetable processing for juice production. Since residual amounts of total organic solids (TOS) are removed by distillation and by the purification steps applied to produce glucose syrups, dietary exposure was not calculated for these two food processes. For the remaining four processes, dietary exposure to the food enzyme–TOS was estimated to be up to 7.7 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not raise a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 3,795 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure above 490. Similarity of the amino acid sequence of the food enzyme to those of known allergens was searched for and one match found. The Panel considered that, under the intended conditions of use (other than distilled alcohol production) the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Genomic and AntiSMASH Analyses of Marine-Sponge-Derived Strain Aspergillus niger L14 Unveiling Its Vast Potential of Secondary Metabolites Biosynthesis.

Aspergillus niger is one of the most important sources of secondary metabolites (SMs), with a wide array of pharmacological effects, including anti-inflammatory, antitumor, immunomodulatory and antioxidant effects. However, the biosynthetic analysis of these bioactive components has been rarely reported owing to the lack of high-quality genome sequences and comprehensive analysis. In this study, the whole genome of one marine-sponge-derived strain A. niger L14 was sequenced and assembled as well as in-depth bioinformatic analysis. The results indicated that the sequence assembly of strain L14 generated one high-quality genome with a total size of 36.1 Mb, a G + C content of 45.3% and an N50 scaffold of 4.2 Mb. Gene annotation was extensively deployed using various BLAST databases, including non-redudant (Nr) protein sequence, nucleotide (Nt) sequence, Swiss-Prot, Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Clusters of Orthologous Groups (COG) as well as Pathogen Host Interactions (PHI) and Carbohydrate-active enzymes (CAZy) databases. AntiSMASH analysis revealed that this marine strain harbors a total of 69 SMs biosynthesis gene clusters (BGCs), including 17 PKSs, 18 NRPSs, 21 NRPS-likes, 9 terpenes, 2 indoles, 1 betalactone and 1 siderophore, suggesting its biosynthetic potential to produce a wide variety of SMs. These findings will assist in future investigations on the genetic basis of strain L14 and provide insights into its new bioactive SMs for new drug discovery.

Antimicrobial activity of chitosan film containing nanocomposite of Trachyspermum ammi (ajwain) seed oil loaded Halloysite nanotubes against foodborne pathogenic microorganisms

Ajwain seed oil (ASO) is a volatile organic compound possessing antimicrobial properties against a wide range of microorganisms. Halloysite nanotubes (Hal) are aluminosilicate natural clay minerals with about 200–2000 nm in length and diameters between 10-50 nm. The structure of Hal allows a sustained release of antimicrobial agents to microbial cells which can be beneficial in the food packaging field. In this work, we loaded ASO into Sodium hydroxide (NaOH) treated Hal and further incorporated it with chitosan to develop an innovative antimicrobial food packaging nanocomposite film. The developed nanocomposite films were characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy, Raman Spectroscopy, Differential scanning calorimetry, Field emission scanning electron microscopy and X-ray diffraction. The antimicrobial properties of the developed nanocomposites were studied against two bacterial strains (Escherichia coli and Bacillus mojavensis) and two fungus strains (Aspergillus niger and Aspergillus flavus) potential food spoilage microorganisms. The nanocomposite (ASO-NaOH-Hal) prevented the growth of Esherichia coli up to 99%, Bacillus mojavensis up to 95%, Aspergillus niger about 97%, and Aspergillus flavus about 97% at concentrations of 5 mg/ml, 7 mg/ml, 5 mg/ml and 5 mg/ml, respectively. And the chitosan film containing ASO-NaOH-Hal presented a clear zone of inhibition against the above-mentioned bacterial strains and inhibited the growth of fungus on the tomato's surfaces therefore, this nanocomposite film could find application in the food packaging field owing to its antimicrobial and antioxidant properties.

Genome-Based Analysis of Aspergillus niger Aggregate Species from China and Their Potential for Fumonisin B2 and Ochratoxin A Production

Based on entire genome sequencing, this study focused on the classification of Aspergillus niger aggregation species and investigated their potential for fumonisin B2 (FB2) and ochratoxin A (OTA) production. In the current study, 22 strains were used, namely 17 A. niger strains, four A. welwitschiae strains, and one A. lacticoffeatus (a synonym of A. niger) strain. Traditional multigene phylogenetic analysis, average nucleotide identity analysis (ANI), and the whole-genome single-nucleotide polymorphism (SNP) analyses were used to reconfirm the taxonomic status of A. niger, A. welwitschiae, and A. lacticoffeatus. The ability of A. niger to produce FB2 and OTA on five culture substrates was determined, and the association between FB2 and OTA gene clusters and toxin-producing abilities was explored. The results revealed that the ANI method could distinguish A. niger from A. welwitschiae, with an ANI value of < 98%. The SNP-based phylogenetic analysis suggested that A. niger and A. welwitschiae were two independent phylogenetic species. The ANI, SNP, and multigene phylogenetic analysis supported previous findings that A. lacticoffeatus was a synonymous species of A. niger. Aspergillus niger strains exhibited the varied potential of producing FB2 and OTA on different culture media. The A. niger genome sequence analysis revealed no significant difference in fumonisin gene clusters between FB2-nonproducing isolates and FB2-producing isolates, and the integrity of the ochratoxin biosynthesis genes cluster was clearly associated with OTA production. In conclusion, gene sequencing can be useful in assessing A. niger's ability to produce OTA, but it cannot reliably predict its ability to produce FB2.

Degradation of Ochratoxin A by a UV-Mutated Aspergillus niger Strain.

Ochratoxin A (OTA) is a mycotoxin that can contaminate a wide range of crops such as grains and grapes. In this study, a novel fungal mutant strain (FS-UV-21) with a high OTA degradation rate (74.5%) was obtained from Aspergillus niger irradiated with ultraviolet light (15 W for 20 min). The effect of pH, temperature, and inoculation concentration on the degradation of OTA by FS-UV-21 was investigated, and the results revealed that the detoxification effect was optimal (89.4%) at a pH of 8 and a temperature of 30 °C. Ultra-performance liquid chromatography-tandem mass spectrometry was used to characterize the degraded products of OTA, and the main degraded product was ochratoxin α. Triple quadrupole-linear ion trap-mass spectrometry combined with LightSight software was used to analyze the biotransformation pathway of OTA in FS-UV-21, to trace the degraded products, and to identify the main metabolite, P1 (C19H18ClNO6, m/z 404). After the FS-UV-21 strain was treated with OTA, the HepG2 cellular toxicity of the degradation products was significantly reduced. For the real sample, FS-UV-21 was used to remove OTA from wheat bran contaminated by mycotoxins through fermentation, resulting in the degradation of 59.8% of OTA in wheat bran. Therefore, FS-UV-21 can be applied to the degradation of OTA in agricultural products and food.

Production of Cellulase by A. Niger and T. Reesei Under Solid State Fermentation Using Bagasse as Substrate

Cellulase is a very important enzyme for ethanol production from lignocellulose and others. Bagasse is very good to be chosen as lignocellulosic material for cellulase production because it is cheap and already available in a huge amount. Solid-state fermentation has advantages than submerged fermentation because of its higher yield and activity. Cellulase production using solid-state fermentation has been researched by many people, but for different substrate, different pretreatment and different fungi producer, it is likely to have a different condition. It is very important to perform specific study to optimize cellulase production with specific substrate and specific fungi which available in Indonesia. Because large amount of fungi strains available so it is wise full if they are screened using effective and efficient methods. This research is started by initial screening of three strain of Trichoderma reesei and five strain of Aspergillus niger using Congo red dye staining on CMC agar plate. It is shown that a strain of Trichoderma reesei and two strains of Aspergillus niger has better activity than the others. Further screening is performed by conducting solid-state fermentation using bagasse by three best strains for five days. The activity of the cellulase is measured every 24-hour using Ghose method by dinitrosalicylic acid as reagent. The highest activity is shown by A.niger ITBCC L74 on third day at 0.525 Unit/gram

Short Communication: Identification of phytochemical constituents of Syzygium aromaticum L. using gas chromatography coupled with mass spectrometry and evaluation of antimicrobial activity

Abstract. Benmakhlouf Z, Benserradj O, Kellab R. 2022. Short Communication: Identification of phytochemical constituents of Syzygium aromaticum L. using gas chromatography coupled with mass spectrometry and evaluation of antimicrobial activity. Biodiversitas 23: 2586-2593. Syzygium aromaticum L. is a traditional spice that has various pharmacological activities attributed to its content of bioactive molecules. The purpose of this work is to evaluate phytochemical constituents of S. aromaticum L. extract using gas chromatography coupled spectrometry mass (CG/MS). The number detected of phenolic compounds was 45, which the most abundant being eugenol (54.63%), followed by Phenol,2-metoxy-4-(2-propenyl)-, acetate (eugenol acetate) (21.57%) and caryophyllene (16.71%). In addition, the antimicrobial activity was screened by the paper disc diffusion method for three bacterial strains, (Pseudomonas aeruginosa ATCC 27853, Salmonella sp. and Staphylococcus aureus 6538) and by the direct contact method on three fungal strains (Aspergillus niger, Aspergillus flavus and Candida albicans). The results showed that extract presents an inhibitory activity with all the strains tested. Salmonella sp. is very sensitive (++) to the stock solution (100mg/ml), sensitive (+) to dilutions (50 and 25) mg/ml with inhibition diameters of (16, 12, 10) mm respectively. The other bacterial strains are sensitive (+) only to the stock solution. The results of our experiment confirm that fungi strains: A. niger, A. flavus and C. albicans show a remarkable antifungal activity at 100mg/ml. The result indicated that the extract obtained from dried buds of S. aromaticum could be considered an agent for antibacterial and antifungal in the pharmaceutical field.

Antifungal Activity of Finished Chromium Tanned Leather Containing Thyme and Tea Tree Essential Oils

Abstract Leather products provide an ideal environment for microbial growth. In order to prevent the appearance and spread of various types of microorganisms, it is treated with selected biocides and even essential oils. The aim of this paper was to investigate the antifungal activity of selected essential oils applied to finished chromium tanned leather which is intended for leather fancy products. Antifungal activity was evaluated according to the PN-EN 14119: 2005 standard. Four finished chromium tanned leathers were tested, each of which was soaked in the following essential oils: tea tree essential oil at a concentration of 1, 2 and 5% and thyme essential oil at concentration of 1, 2 and 5%. The results obtained indicated that leather finishing with thyme essential oil showed the antimicrobial activity against Aspergillus niger, Chaetomium globosum and Candida albicans strains. The application of 5% thyme essential oil to leather samples inhibited the growth of all strains tested. Using tea tree essential oil on leather samples showed a antimicrobial effect only against Candida albicans. The application of essential oils in the leather finishing process may be an alternative to biocides used in the tanning industry.

Safety evaluation of the food enzyme pectin lyase from the genetically modified Aspergillus luchuensis strain FLOSC.

The food enzyme pectin lyase ((1→4)‐6‐O‐methyl‐α‐d‐galacturonan lyase; EC 4.2.2.10) is produced with the genetically modified Aspergillus luchuensis (formally Aspergillus niger) strain FLOSC by Advanced Enzyme Technologies Ltd. The genetic modifications do not give rise to safety concerns. The food enzyme is free from viable cells of the production organism and its DNA. The food enzyme is intended to be used in fruit and vegetable processing for juice production. Based on the maximum use level and individual data from the EFSA Comprehensive European Food Database, dietary exposure to the food enzyme–total organic solids (TOS) was estimated to be up to 0.268 mg TOS/kg body weight (bw) per day in European populations. Genotoxicity tests did not indicate a safety concern. The systemic toxicity was assessed by means of a repeated dose 90‐day oral toxicity study in rats. The Panel identified a no observed adverse effect level of 794 mg TOS/kg bw per day, the highest dose tested, which when compared with the estimated dietary exposure, results in a margin of exposure of at least 2,900. A search for similarity of the amino acid sequence of the food enzyme to known allergens was made and no match was found. The Panel considered that, under the intended conditions of use the risk of allergic sensitisation and elicitation reactions by dietary exposure cannot be excluded, but the likelihood for this to occur is considered to be low. Based on the data provided, the Panel concluded that this food enzyme does not give rise to safety concerns under the intended conditions of use.

Antimicrobial Activity and Phytochemical Analysis of Capparis grandis Linn

Capparis grandis Linn. is a species of the family Capparidaceae. It is commonly known as ‘Pachunda’. The main objective of the present study was to investigate the antimicrobial activity and phytochemical analysis of an aqueous extract of Capparis grandis Linn. Medicinal plants have an alternative rich source of phytochemicals and antibacterial agents. The phytochemical result showed the presence of carbohydrate, steroid, alkaloid, flavonoid, tannin, and glycosides. The antibacterial activity was studied by the agar well diffusion method using an aqueous extract of Capparis grandis Linn. leaves. This extract was tested against five bacterial strains Pseudomonas, Bacillus pasteurii, Escherichia coli, Bacillus subtilis, Streptococcus mutant, and three fungal strains Candida albicans, Aspergillus niger, and Dreschlera turcica. This result shows that the leaves of this plant have a potentially broad-spectrum antibacterial activity and phytochemical constituents and these help in the production and development of phytomedicines for antibacterial or antimicrobial properties.

Survival and growth of microscopic fungi derived from tropical regions under future heat waves in the Pannonian Biogeographical Region

Warming and heat waves are predicted by different climate models in the near future in the Pannonian Biogeographical Region (PBR). These climatic effects may have impact on the prevalence and distribution of certain fungal species of this area. In this study the effects of predicted climate scenarios were tested on fungi being endemic or unintentionally introduced by global trade from regions of warm temperate climate. Common fungal species were selected for the study and exposed to heat waves during 7 days according to two climate scenarios: one moderately (RCP 4.5, Tavg = 27 °C, Tmax = 35 °C, RH: 100%) and one strongly pessimistic (RCP 8.5, Tavg = 30 °C, Tmax = 40 °C, RH: 100%) that include predictions for the Central Hungarian Region for July 2050. According to our results, Aspergillus flavus, Aspergillus niger, Aspergillus tubingensis and Fusarium strains introduced from tropical regions tolerated heat waves, unlike Penicillium and Talaromyces spp. and endemic Cladosporium spp. which were unable to grow under the RCP 8.5 treatment. The effects of climate change on fungi raise new issues not only from economic and health perspectives, but also in relation with plant protection and environment. Our results suggest that heat waves driven by climate change promote the colonization and growth of the tested strains of non-native fungi more likely than that of the native ones.

Mycosynthesis, Characterization, and Mosquitocidal Activity of Silver Nanoparticles Fabricated by Aspergillus niger Strain.

Herein, silver nanoparticles (Ag-NPs) were synthesized using an environmentally friendly approach by harnessing the metabolites of Aspergillus niger F2. The successful formation of Ag-NPs was checked by a color change to yellowish-brown, followed by UV-Vis spectroscopy, Fourier transforms infrared (FT-IR), Transmission electron microscopy (TEM), and X-ray diffraction (XRD). Data showed the successful formation of crystalline Ag-NPs with a spherical shape at the maximum surface plasmon resonance of 420 nm with a size range of 3–13 nm. The Ag-NPs showed high toxicity against I, II, III, and IV instar larvae and pupae of Aedes aegypti with LC50 and LC90 values of 12.4–22.9 ppm and 22.4–41.4 ppm, respectively under laboratory conditions. The field assay exhibited the highest reduction in larval density due to treatment with Ag-NPs (10× LC50) with values of 59.6%, 74.7%, and 100% after 24, 48, and 72 h, respectively. The exposure of A. aegypti adults to the vapor of burning Ag-NPs-based coils caused a reduction of unfed individuals with a percentage of 81.6 ± 0.5% compared with the positive control, pyrethrin-based coils (86.1 ± 1.1%). The ovicidal activity of biosynthesized Ag-NPs caused the hatching of the eggs with percentages of 50.1 ± 0.9, 33.5 ± 1.1, 22.9 ± 1.1, and 13.7 ± 1.2% for concentrations of 5, 10, 15, and 20 ppm, whereas Ag-NPs at a concentration of 25 and 30 ppm caused complete egg mortality (100%). The obtained data confirmed the applicability of biosynthesized Ag-NPs to the biocontrol of A. aegypti at low concentrations.

Insight into the antifungal effect of chitosan-conjugated metal oxide nanoparticles decorated on cellulosic foam filter for water filtration

Worldwide, fungal contamination of water resources has become a major threat to both human health and the environment. The adaptation of nanotechnology in conventional water processes is significant to offer new breakthroughs in water treatment, especially fungal contaminants. Chitosan conjugated metal oxide nanoparticles can affect the antimicrobial properties of cellulosic foam. In the present study, three different types of biocompatible nanoconjugates (i.e., ZnO/chitosan, CuO/chitosan, and Ag2O/chitosan) were synthesized for functionalization of five differently processed cellulose foam filters for resisting fungal spores during water treatment. To evaluate the antifungal effect of these nanoconjugates against prevalent strains of Aspergillus niger (A. niger), Aspergillus flavus (A. flavus), and Rhizopus oryzae (R. oryzae), the stable coating was introduced on different cellulose filter papers through impregnation. The statistical analysis of antifungal experiment was carried out by two-way factorial ANOVA test. Cellulose filter containing ZnO/chitosan displayed a stronger antifungal behavior in disc diffusion method than those impregnated with CuO/chitosan, and Ag2O/chitosan nanoconjugates. Besides the choice of nanoconjugates, the variation in cellulose foam filters (in terms of concentration of their raw materials and/or processing methodology) can also affect their antifungal performance. Further, the assessment of cytotoxic nature of such nanocomposites-modified cellulose foam filters is a fundamental step towards their real field applications.